The present disclosure relates generally to spray systems and, more particularly, to control systems for use with spray systems and methods of controlling spray systems.
Spraying is a well-known method of applying a wide variety of bulk materials, primarily in liquid form or a mixture of liquid and powder in a fluid propellant medium. Such spray materials can be dispensed in air currents, under liquid pressure, by gravity flow, or with any other suitable discharge means. Spray application of bulk materials may offer a variety of potential advantages, including efficiency, uniformity of coverage, and flexibility to adapt spraying equipment to various conditions unique to the objects being sprayed and their particular environments.
The field of agricultural spraying is a relatively large industry and may include pesticide application for crop pest management and the application of fertilizer and growth regulators for nutrient management. The use of pesticides in agricultural applications may produce substantial benefits in crop yields with a potentially large amount of estimated savings in crops which may otherwise have been lost to pests. Similarly, the spray application of fertilizers and growth regulators may also produce substantial benefits in crop yields and the like.
Notwithstanding the potential advantages of agricultural spraying applications of pesticides and other spray materials, agricultural spraying may generally be a relatively inefficient process. Factors which contribute to such inefficiencies include the susceptibility of sprayed materials to wind drift, overspray, and inaccurate placement on the intended target crop plants. Irregularities in terrain and non-uniform plantings also contribute to the inconsistent and inefficient application of agricultural spray materials. Moreover, variations in ambient conditions such as wind, humidity levels, and temperature tend to reduce the uniformity and efficiency with which spray materials are applied to their intended crop targets.
Certain of these problems associated with the misapplication of agricultural spray materials may in some cases be exacerbated by the use of larger spraying equipment covering wider swaths, high speed vehicles, air-blast spraying, and by aerial spraying. However, the inherent difficulties associated with large-scale spraying operations may be balanced against the relative efficiencies which are achieved by covering larger areas more rapidly with wide-swath spraying equipment.
Certain of the above problems may be addressed by control of an application rate of the spray liquid. A common technique for controlling the application rate of spray liquid involves adjusting the spray liquid pressure, for example, with the use of a throttling valve in a main distribution line of a spray liquid distribution system. However, altering the liquid pressure also generally alters a droplet size of the spray, thus effecting the deposition and its susceptibility to spray drift, evaporation, and other factors.
Accordingly, a spray system that is capable of controlling the application rate of the spray liquid while maintaining a consistent liquid pressure would be particularly useful.